A reservoir is provided in a power steering system to hold a predetermined quantity of hydraulic fluid. Typically, the reservoir has an outlet port that communicates fluid to a power steering pump and an inlet port that returns fluid from a power steering gear back into the reservoir. It is also known to provide a filter inside the reservoir to filter the fluid as it flows from the inlet port to the outlet port.
However, one draw back of such known reservoirs is that hydraulic fluid does not flow fast enough through the filter during cold temperature operation. The colder the hydraulic fluid, the greater the resistance to flow. Such increased viscosity greatly reduces the ability of the fluid to pass through the filter. As a result, an insufficient amount of fluid is supplied to the pump. The insufficient amount of fluid causes cavitation within the pump, which produces undesirable noise and sound.
One known reservoir design has attempted to diminish cold weather effects. The known reservoir utilizes a relatively complex series of angled guide members and a series of filter elements to control the directional flow of fluid returning from the inlet port to the outlet port. However, the elaborate guide system is costly to manufacture and has an unnecessarily large number of parts.